(19) TZZ __T

(11) EP 2 626 521 B1

(12) EUROPEAN PATENT SPECIFICATION

(45) Date of publication and mention (51) Int Cl.: of the grant of the patent: F01D 17/16 (2006.01) F01D 17/20 (2006.01) 26.07.2017 Bulletin 2017/30 F04D 29/56 (2006.01) F16H 1/28 (2006.01)

(21) Application number: 13154356.3

(22) Date of filing: 07.02.2013

(54) A Unison Ring Assembly for a gas turbine Verstellringgetriebeanordnung einer Gasturbine Ensemble d’engrenages d’anneau de conjugaison d’une turbine à gaz

(84) Designated Contracting States: (72) Inventor: Coles, David AL AT BE BG CH CY CZ DE DK EE ES FI FR GB Derby, Derbyshire DE73 6XH (GB) GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR (74) Representative: Rolls-Royce plc Intellectual Property Dept SinA-48 (30) Priority: 13.02.2012 GB 201202383 PO Box 31 Derby DE24 8BJ (GB) (43) Date of publication of application: 14.08.2013 Bulletin 2013/33 (56) References cited: EP-A2- 2 053 204 US-A- 3 632 224 (73) Proprietor: Rolls-Royce plc US-A- 6 039 534 London SW1E 6AT (GB)

Note: Within nine months of the publication of the mention of the grant of the European patent in the European Patent Bulletin, any person may give notice to the European Patent Office of opposition to that patent, in accordance with the Implementing Regulations. Notice of opposition shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). EP 2 626 521 B1

Printed by Jouve, 75001 PARIS (FR) 1 EP 2 626 521 B1 2

Description major axis of the vane which is coincidental with the ro- tational axis of the spindle. The unison rings 212 are ar- Technical Field of Invention ranged such that rotating them around the principal axis of the engine results in the lever arms 214 pivoting about [0001] This invention relates generally to an actuation 5 the vane spindles, thereby rotating them and the aerofoil for variable vanes in an axial flow gas turbine portions within the airflow channel of the compressor 18. engines. The vanes are variable in that they are rotatable [0006] To rotate the unison rings, an input link is pro- about their major axis such that the delivery angle of fluid vided to engage with a which drives the unison flow to a rotor stage of a compressor or the like may be rings via link rods. As the levers rotate around the centre altered to benefit the performance of the engine. Al-10 of rotation of the vane spindles, the lever arms fixed in- though principally geared towards gas turbine engines, terface with the unison ring requires that the unison ring the invention may be applicable to other engines or de- translates axially as well as circumferentially as it trans- vices which have arrays of rotatable members. lates. [0007] This design requires that all the interfaces be- Background of Invention 15 tween moving components have bushes fitted to accom- modate the necessary movement. Additionally, to keep [0002] Figure 1 shows a ducted fan gas turbine engine the unison rings circular as they accommodate the loads 10 comprising, in axial flow series: an air intake 12, a within the system, the rings are fitted with centralising propulsive fan 14 having a plurality of fan blades 16, an features that contact the casings to maintain roundness. intermediate pressure compressor 18, a high-pressure 20 This can be achieved by using mushroom headed bolts compressor 20, a combustor 22, a high-pressure turbine or centralising screws which contact pads that are bond- 24, an intermediate pressure turbine 26, a low-pressure ed or bolted to the engine casing. turbine 28 and a core exhaust nozzle 30. A nacelle 32 [0008] This assembly is unnecessarily complex and generally surrounds the engine 10 and defines the intake heavy. 12, a bypass duct 34 and a bypass exhaust nozzle 36. 25 [0009] US3632224 describes a gas turbine engine in The engine has a principal axis of rotation 44. which the turbine nozzle vanes and turbine outlet guide [0003] Air entering the intake 12 is accelerated by the vanes are simultaneously pivotal to obtain greater effi- fan 14 to produce a bypass flow and a core flow. The ciencies over a broad range of gas stream energy levels. bypass flow travels down the bypass duct 34 and exits [0010] The present invention seeks to provide an al- the bypass exhaust nozzle 36 to provide the majority of 30 ternative arrangement. the propulsive thrust produced by the engine 10. The core flow enters in axial flow series the intermediate pres- Statements of Invention sure compressor 18, high pressure compressor 20 and the combustor 22, where fuel is added to the compressed [0011] In a first aspect, the present invention relates air and the mixture burnt. The hot combustion products 35 to a unison ring assembly for actuating first and second expand through and drive the high, intermediate and low- unison rings which are connected to variable stator guide pressure turbines 24, 26, 28 before being exhausted vanes when in use, comprising: a first unison ring and a through the nozzle 30 to provide additional propulsive second unison ring concentrically aligned along a princi- thrust. The high, intermediate and low-pressure turbines pal axis, the first and second rings being rotatable about 24, 26, 28 respectively drive the high and intermediate 40 the principal axis; and, a gear mechanism for simultane- pressure compressors 20, 18 and the fan 14 by intercon- ously rotating the first and second unison rings about the necting shafts 38, 40, 42. principal axis, wherein the gear mechanism includes a [0004] It is commonplace in state of the art gas turbine sun planet gear arrangement and characterised in that: engines 10 to include variable vanes at various locations the planet gear is eccentrically mounted so as to have a in the engine to generally help control the air flow passing 45 rotational axis which is offset by different amounts rela- through the engine core, thus improving the performance tive to each of the first and second unison ring such of the engine. Figure 2 illustrates a typical Variable Stator that a range of angular rotation of each unison ring is Vane assembly 210 which is used in various engines for different for a common angle of rotation from the planet aerospace, industrial and marine applications. gear. [0005] The assembly includes four unison rings 212 50 [0012] The first unison ring may be the ring gear and coaxially arranged relative to the principal axis 44 of the the second unison ring may be the sun gear. engine 10 around the exterior of the intermediate com- [0013] The planet gear may include a first section pressor 18 (not shown in Figure 2). Each unison ring 212 which engages with the ring gear and a second section has a plurality of lever arms 214 each of which attach to which engages with the sun gear. The gear ratio of the a vane spindle (not shown) via the mounting holes 216 55 first and second sections may be different. located in the distal end thereof. The aerofoil portions of [0014] The first unison ring may be radially outwards the vanes are rotatably mounted within the airflow path of the second unison ring with respect to the principal of the compressor 18 such that they can rotate about the axis of the engine.

2 3 EP 2 626 521 B1 4

[0015] The unison ring assembly may further comprise rotational adjustment to a plurality of rows of variable a plurality of planet gears distributed around the unison vanes 312 in an annular compressor of a axial flow gas ring gears. The plurality of planet gears may be arranged turbine engine, similar to the one shown in Figure 1. to concentrically align the unison ring gears about the [0022] In Figure 3 there is shown a portion of a com- principal axis. Thus, there may be provided a unison ring 5 pressor 314 having a first stage 316 and a second stage assembly wherein the first and second unison rings in- 318 of variable vanes 312 which are arranged in axial clude radially facing surfaces which oppose one another, flow series, the axial flow being referenced by arrow 320. andthe assembly may furthercomprise a plurality ofplan- In the described embodiment, the variable vanes 312 are et gears distributed around the unison ring gears be- stator vanes (VSVs), but the invention may be of broader tween the radially facing surfaces, such that the planet 10 application within a gas turbine engine, or elsewhere. It gears concentrically align the unison ring gears about is to be noted that although Figure 3 only shows one vane the principal axis. per stage, this is one of an annular array of blades. Fur- [0016] The first and second unison rings may include ther, although not shown, the variable vanes 312 will be axiallyfacing surfaceswhich oppose oneanother, where- interspersed with rotors having rotor blades in a working in the or each planet gear may be provided between the 15 engine, as is well known in the art. Further, there may be opposing surfaces and axially locate the sun and planet more than two rows of variable vanes. Indeed, it is well gears relative to the principal axis. known to have at least four VSVs in a gas turbine engine. [0017] The rotational axis of the or each planet gear [0023] Each of the VSV’s includes an aerofoil portion may angularly offset with regard to the principal axis such 322 which is located within the airflow 320 channel of the that the or each planet gear axially and radially aligns the 20 compressor 314 and is mounted therein so as to be ro- first and second unison rings. tatable about a radially extending major axis 324 of the [0018] The unison ring assembly may further comprise vane. The radially outer end of the aerofoil portion 322 at least one actuator connected to and configured to di- of the vane 312 adjoins a spindle 326 which is coaxial rectly rotate one of the ring gear, planet or sun gear. with the rotational, major axis 324 of the vane 312 and [0019] The unison ring assembly is for a gas turbine 25 which projects through the compressor wall 328 into the engine. The first and second unison rings may be con- space which occupies the unison ring gear 310. The spin- nected to variable stator guide vanes. dle 326 engages with the unison ring gear 310 which is actuable so as to rotate the spindle 326 and thus the Description of Drawings angle of the VSV 312 relative to the direction of the gas 30 flow in the compressor when in use. Hence, in use, the [0020] The following drawings are used to describe gas flow delivery angle of the vane 312 can be adjusted embodiments of the present invention. as required for a particular performance. [0024] The unison ring assembly 310 includes a first Figure 1 shows a known ducting fan gas turbine en- unison ring 330 and a second unison ring 332, each being gine. 35 associated with and arranged to rotate a stage of VSV’s 316, 318. The unison rings 330, 332 are rotatably mount- Figure 2 shows a known unison ring assembly. ed about the principal axis of the engine and are engaged and simultaneously driven by a single gear 334 so as to Figure 3 shows a cross section of a unison ring as- rotate the unison rings. sembly according to the invention. 40 [0025] The engagement between the unison rings 330, 332 and the respective spindles 326 is by way of a rack Figure 4 shows an axial view of a planet gear of an and type of arrangement in which the spindles 326 embodiment of the invention. of the VSVs 312 carry a flange 336 or lever arm which has a toothed rim 338 so as to effectively provide a cog, Figure 5 shows an alternative embodiment of the 45 or pinion, for engagement with a corresponding geared present invention. section 340, or rack, on its respective unison rings 330, 332. Figure 6 shows a yet further embodiment of the [0026] An axial view of the gear mechanism 334 which present invention. drives the unison rings 330, 332 of the described embod- 50 iment is shown in Figure 4. The gear mechanism is in Figure 7 shows various driving mechanisms for ro- theform of a sunand planet gear system having a plurality tating the unison rings. of type gears to translate the force be- tween the respective members of the arrangement. In Detailed Description of Invention the embodiment, the first unison ring 330 provides the 55 ring gear, the second unison ring 332 provides the sun [0021] In Figure 3 there is shown a unison gear ring gear, and a driving member 334 provides the planet gear. assembly 310 according to the present invention. The The driving member 334 includes two opposing arcuate unison gear ring assembly 310 is arranged to provide segments 339 of plate having a toothed rim 340 which

3 5 EP 2 626 521 B1 6 engages with a corresponding toothed section 341 on unison rings 330, 332 may not be L shaped, but may be the unison ring 332. The driving member 334 is rotatably box sections or some other shape which provides the mounted on a spindle 342 which is cantilevered from the necessary rigidity. Further, the unison rings 330,332 may wall of the compressor 328 or other suitable structure. include weight saving or strengthening features not de- The arrangement is such that rotating the driving member 5 scribed here, but which may affect the overall shape of 336 results in a rotation of the unison rings 330, 332, the unison rings 330, 332. which, in turn, rotates the respective VSVs 312 via the [0031] In another embodiment, as shown in Figure 5, spindles 326. the unison rings 530, 532 each comprise a radially ex- [0027] In the described embodiment, the driving mem- tending plate having toothed sections on both axially fac- ber 334 is asymmetric in that it is eccentrically mounted 10 ing surfaces. The two unison rings 530, 532 are substan- on the spindle 342. Thus, the distance from the spindle tially similar and oppose one another along the longitu- 342 to the each respective unison ring 330,332 is differ- dinal axis of the engine so as to provide in axial series a ent. Specifically, the distance between the first unison toothed flange 536 of the first stage vane spindle, a first ring 330 and spindle 342 is greater than that of the spindle unison ring 530, a driving member 534, a second unison 342to the second unisonring 332. With this arrangement, 15 ring 532 and a second toothed spindle flange 538, with the gear ratio between the driving member and each uni- the driving member 534 sitting in a tangential plane rel- son ring can be different and thus the range of travel of ative to the principal axis of the engine. Thus, the unison one unison ring 330,332 can be different to that of the rings are maintained in place between the two spindles other. This means that the range of angular rotation of 526 and driving member 534 so there is no axial displace- each unison ring and the associated deflection experi- 20 ment of the unison rings during use. enced by each VSV 312 can be different for a common [0032] It is of note that the first and second unison rings angle of actuation from the driving member 334 which 530, 532 shown in Figure 5 have different radial lengths can be advantageous. As can be seen from Figure 4, the with the racks of the first unison gear 530 opposing each number and pitch of the gear teeth 340 for each of the other at a common radial distance from the principal axis unison rings 330,332 may be different so as to accom- 25 of the engine, but with the racks of the second unison modate this difference in gearing. ring gear 532 being radially offset. This allows for a com- [0028] In more detail, the unison rings 330,332 can be mon length of spindle 526 to be accommodated for each described as having an annular radial face 344 and an stage of the compressor 18 when the compressor has a axially facing surface 346. In the described embodiment, generally convergent geometry and thus inclined walls these are provided by having a unison ring 330,332 which 30 relative to the principal axis 44 of the engine. A technical is substantially L shaped in cross section which compris- advantage of the two embodiments described above is es a radially extending annular plate lying perpendicular that the rotational forces exerted to on the unison rings relative to the principal axis of the engine and, adjoined 330, 332, 530, 532 and spindles 326, 526 are all about to one end of the plate, an annular flange which extends constant axes of rotation before, during and after rotation. in an axial direction so as to form a short cylindrical por- 35 Hence, no axial or radial translation of the unison rings tion. Thus, a surface of the annular plate provides the 330, 332, 530, 532 or spindles 326, 526 occurs in use. axially facing surface 344 and cylindrical section provides [0033] Thus, the requirements from the supporting the radially facing surface 346, each having a toothed mechanisms are simplified and the loads can be sub- section for engagement with driving member 334. stantially carried by the spindles and driving members [0029] In the described embodiment, the unison ring 40 334, 534. members 330,332 are placed in a radially separated [0034] In yet a further embodiment as shown in Figure manner such that radially facing surfaces of each unison 6, the rotational axis of the driving member 634 is angu- ring member, and the respective toothed sections, op- larly offset with regard to the principal axis 44 of the en- pose one another. In this way, the unison rings are bal- gine, rather than being axially or radially aligned to the anced across the driving member 334 and the spacing 45 principal axis 44. In this way, the driving member 634 between the unison ring members 330, 332 can be main- can be arranged to resolve or balance out the radial and tained by the driving members 334. This is particularly axial forces of the unison rings 630, 632 between the advantageous where a plurality of the driving members spindles 626 and unison rings 630, 632, thereby central- 336 are spaced around the compressor 18 in a circular ising and retaining the unison rings in place. array, as it naturally retains the unison ring 330, 332 in 50 [0035] With reference to Figure 7 and the above de- concentric relation to each other and removes, or at least scribed embodiments, the unison rings 730, 732 and driv- reduces, the need to have other centralising features. ing members 734 are interlocked such that rotating one Such features can be found in the prior art systems and of them results in the other two being rotated by a corre- would include the centralising screws and pads as men- sponding and proportional amount. Thus, as shown in tioned above in the background section. 55 Figure 7, any of the gears can be attached to an actuation [0030] It will be appreciated that variations in the con- system 736 to provide the required rotative force. The structional detail of the described embodiment are pos- actuation system 736 may be any suitable system known sible within the scope of the invention. For example, the in the art such as electrical, pneumatic or hydraulic. The

4 7 EP 2 626 521 B1 8 attachment between the respective gear and the actua- and the assembly further comprises a plurality of tion system can also be any suitable attachment as planet gears (334,534,634) distributed around the known in the art. unison rings between the radially facing surfaces [0036] The unison ring gear arrangements described such that the planet gears (334,534,634) concentri- above may be made from metals e.g. steels, aluminum, 5 cally align the unison ring gears about the principal titanium alloys etc. or, where the environment permits, axis (44). composite materials may be considered for the gears to give a light weight design. 6. A unison ring assembly as claimed in any preceding [0037] The inventionis defined by the appended claims claim 2 to 5 wherein the first and second unison rings and the above described embodiments should not be 10 include axially facing surfaces which oppose one an- taken as limiting the scope of those claims. other and wherein the or each planet gear (534) is provided between the opposing surfaces and axially locates the sun and planet gears relative to the prin- Claims cipal axis (44). 15 1. A unison ring assembly (310) for actuating first and 7. A unison ring assembly as claimed in any of claim 6 second unison rings (330, 530, 630, 332, 532, 632) wherein the rotational axis of the or each planet gear which are connected to variable vanes (312, 316, (634) is angularly offset with regard to the principal 318) of an axial flow turbine when in use, comprising: axis (44) such that the or each planet gear (634) 20 axially and radially aligns the first and second unison a first unison ring (330, 530) and a second uni- rings. son ring (332, 532) 532,632) concentrically aligned along a principal axis (44), the first and 8. A unison ring assembly as claimed in any preceding second rings being rotatable about the principal claim further comprising at least one actuator (736) axis; and, 25 connected to and configured to directly rotate one of a gear mechanism for simultaneously rotating the ring gear, planet or sun gear. the first and second unison rings about the prin- cipal axis (44), wherein the gear mechanism in- 9. A unison ring assembly as claimed in any preceding cludes a sun planet gear arrangement and is claim wherein the unison ring assembly is for a gas characterised in that: the planet gear (334, 30 turbine engine 534, 634) is eccentrically mounted so as to have a rotational axis which is offset by different 10. A gas turbine engine comprising a unison ring as- amounts relative to each of the first and second sembly as claimed in any preceding claim. unison ring such that a range of angular rotation of each unison ring is different for a common 35 11. A gas turbine engine as claimed in claim 10, wherein angle of rotation from the planet gear. the first and second rings (330,530,630,332,532, 632) are connected to variable stator guide vanes. 2. A unison ring assembly as claimed in claim 1 wherein the first unison ring (330,530,630) is the ring gear and the second unison ring (332,532,632) is the sun 40 Patentansprüche gear. 1. Verstellringanordnung (310) zum Betätigen erster 3. A unison ring assembly as claimed in any preceding und zweiter Verstellringe (330, 530, 630, 332, 532, claim wherein the planet gear (334,534,634) in- 632), die mit variablen Schaufeln (312, 316, 318) cludes a first section which engages with the ring 45 einer Axialturbine verbunden werden, wenn sie im gear and a second section which engages with the Einsatz ist, umfassend: sun gear and wherein the gear ratio of the first and second sections are different. einen entlang einer Hauptachse (44) konzent- risch ausrichteten ersten Verstellring (330, 530) 4. A unison ring assembly as claimed in any preceding 50 und einen zweiten Verstellring (332, 532) 532, claim wherein the first unison ring (330,530) is radi- 632), wobei der erste und zweite Ring um die ally outwards of the second unison ring (332,532, Hauptachse drehbar sind; und 632) with respect to the principal axis (44). einen Zahnradmechanismus zum gleichzeiti- gen Drehen des ersten und zweiten Verstell- 5. A unison ring assembly as claimed in claim any pre- 55 rings um die Hauptachse (44), wobei der Zahn- ceding claim wherein the first and second unison radmechanismus eine Sonnen-Planetenrad- rings (330,530,630,332,532,632) include radially Anordnung aufweist unddadurch gekenn- facing surfaces (344) which oppose one another, zeichnet wird, dass: das Planetenrad (334, 534,

5 9 EP 2 626 521 B1 10

634) exzentrisch montiert wird, um damit eine 9. Verstellringanordnung nach einem vorhergehenden Drehachse zu haben, die durch unterschiedli- Anspruch,wobei die Verstellringanordnungfür einen che Beträge bezogen auf jeden des ersten und Gasturbinenmotor dient. zweiten Verstellrings so versetzt ist, dass ein Bereich winkelförmiger Drehung jedes Verstell- 5 10. Gasturbinenmotor, der eine Verstellringanordnung rings für einen gemeinsamen Drehwinkel des nach einem vorhergehenden Anspruch umfasst. Planetenrads unterschiedlich ist. 11. Gasturbinenmotor nach Anspruch 10, wobei der ers- 2. Verstellringanordnung nach Anspruch 1, wobei der te und zweite Ring (330,530,630,332,532) mit vari- erste Verstellring (330,530,630) der Zahnkranz ist 10 ablen Statorleitschaufeln verbunden sind. und der zweite Verstellring (332,532,632) das Son- nenrad ist. Revendications 3. Verstellringanordnung nach einem vorhergehenden Anspruch, wobei das Planetenrad (334,534,634) ei- 15 1. Ensemble d’anneaux de conjugaison (310) permet- nen ersten Abschnitt, der mit dem Zahnkranz ein- tant l’actionnement de premier et second anneaux rastet und einen zweiten Abschnitt aufweist, der mit de conjugaison (330, 530, 630, 332, 532, 632) qui dem Sonnenrad einrastet und wobei die Getriebeü- sont raccordés aux aubes à incidence variable (312, bersetzung des ersten und zweiten Abschnitts un- 316, 318) d’une turbine à écoulement axial lors de l’ terschiedlich ist. 20 utilisation, comprenant :

4. Verstellringanordnung nach einem vorhergehenden un premier anneau de conjugaison (330, 530) Anspruch, wobei der erste Verstellring (330,530) be- et un second anneau de conjugaison (332, 532, züglich der Hauptachse (44) radial auswärts des ) 532, 632) alignés de manière concentrique le zweiten Verstellrings (332,532,632) ist. 25 long d’un axe principal (44), les premier et se- cond anneaux pouvant tourner autour de l’axe 5. Verstellringanordnung nach einem vorhergehenden principal ; et, Anspruch, wobei der erste und zweite Verstellring un mécanisme d’engrenages pour faire tourner (330,530,630,332,532,632) radial ausgerichtete simultanément les premier et second anneaux Oberflächen (344) aufweisen, die sich gegenüber- 30 de conjugaison autour de l’axe principal (44), stehen und die Anordnung des Weiteren eine Viel- ledit mécanisme d’engrenage comprenant un zahl von so rund um die Verstellringe zwischen den système d’engrenages planétaire et satellite et radial ausgerichteten Oberflächen verteilte Plane- est caractérisé en ce que : l’engrenage satel- tenräder (334,534,634) umfasst, dass die Planeten- lite (334, 534, 634) est monté de manière ex- räder (334,534,634) die Verstellring-Zahnräder um 35 centré de façon à présenter un axe de rotation die Hauptachse (44) konzentrisch ausrichten. qui est décalé d’une quantité qui diffère par rap- port à chacun des premier et second anneaux 6. Verstellringanordnung nach einem vorhergehenden de conjugaison de sorte que la plage de rotation Anspruch 2 bis 5, wobei der erste und zweite Ver- angulaire de chaque anneau de conjugaison stellring axial ausgerichtete Oberflächen aufweisen, 40 soit différente pour un angle de rotation commun die sich gegenüberstehen, und wobei das oder jedes de l’engrenage satellite. Planetenrad (534) zwischen den entgegengesetz- ten Oberflächen bereitgestellt wird und bezogen auf 2. Ensemble d’anneaux de conjugaison selon la reven- die Hauptachse (44) die Sonnen- und Planetenräder dication 1,ledit premier anneau deconjugaison (330, axial festlegt. 45 530, 630) étant l’engrenage d’anneau et le second anneau de conjugaison (332, 532, 632) étant l’en- 7. Verstellringanordnung nach Anspruch 6, wobei die grenage planétaire. Drehachse des oder jedes Planetenrads (634) In Be- zug aufdie Hauptachse (44) so winkelförmig versetzt 3. Ensemble d’anneaux de conjugaison selon l’une ist, dass das oder jedes Planetenrad (634) den ers- 50 quelconque des revendications précédentes, ledit ten und zweiten Verstellring axial und radial ausrich- engrenage satellite (334, 534, 634) comprenant une tet. première section qui vient en prise avec l’engrenage d’anneau et une seconde section qui vient en prise 8. Verstellringanordnung nach einem vorhergehenden avec l’engrenage planétaire et lesdits rapports d’en- Anspruch, die des Weiteren mindestens einen Ak- 55 grenage des première et seconde sections étant dif- tuator (736) umfasst, der verbunden mit und konfi- férents. guriert wird, um entweder den Zahnkranz, das Pla- neten- oder Sonnenrad direkt zu drehen. 4. Ensemble d’anneaux de conjugaison selon l’une

6 11 EP 2 626 521 B1 12

quelconque des revendications précédentes, ledit premier anneau de conjugaison (330, 530) étant ra- dialement vers l’extérieur du second anneau de con- jugaison (332, 532, 632) par rapport à l’axe principal (44). 5

5. Ensemble d’anneaux de conjugaison selon l’une quelconque des revendications précédentes, lesdits premier et second anneaux de conjugaison (330, 530, 630, 332, 532, 632) comprenant des surfaces 10 (344) radialement en regard s’opposant les unes aux autres, et ledit ensemble comprenant en outre une pluralité d’engrenages satellites (334, 534, 634) ré- partis autour des anneaux de conjugaison entre les surfaces radialement en regard de sorte que les en- 15 grenages satellites (334, 534, 634) alignent de ma- nière concentrique les engrenages d’anneaux de conjugaison par rapport à l’axe principal (44).

6. Ensemble d’anneaux de conjugaison selon l’une20 quelconque des revendications 2 à 5, lesdits premier et second anneaux de conjugaison comprenant des surfaces axialement en regard qui s’opposent les unes aux autres et ledit ou chaque engrenage satel- lite (534) étant disposé entre les surfaces opposées 25 et positionnant axialement les engrenages planétai- re et satellite par rapport à l’axe principal (44).

7. Ensemble d’anneaux de conjugaison selon la reven- dication 6, ledit axe de rotation dudit ou de chaque 30 engrenage satellite (634) présentant un décalage angulaire par rapport à l’axe principal (44) de sorte que ledit ou chaque engrenage satellite (634) aligne axialement et radialement les premier et second an- neaux de conjugaison. 35

8. Ensemble d’anneaux de conjugaison selon l’une quelconque des revendications précédentes, com- prenant en outre au moins un actionneur (736) rac- cordé à l’un parmi l’engrenage d’anneau et l’engre- 40 nage satellite ou planète et configuré pour directe- ment la rotation de celui-ci.

9. Ensemble d’anneaux de conjugaison selon l’une quelconque des revendications précédentes, ledit 45 ensemble d’anneaux de conjugaison étant destiné à un moteur à turbine à gaz.

10. Moteur à turbine à gaz comprenant un ensemble d’ anneaux de conjugaison selon l’une quelconque des 50 revendications précédentes.

11. Moteur à turbine à gaz selon la revendication 10, lesdits premier et second anneaux (330, 530, 630, 332, 532) étant raccordés aux aubes directrices de 55 stator à incidence variable.

7 EP 2 626 521 B1

8 EP 2 626 521 B1

9 EP 2 626 521 B1

10 EP 2 626 521 B1

11 EP 2 626 521 B1

REFERENCES CITED IN THE DESCRIPTION

This list of references cited by the applicant is for the reader’s convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

Patent documents cited in the description

• US 3632224 A [0009]

12